Oscillating actuator



Sept. 6, 1960 R. E. SELF oscILLATING AcTUAToR 2 Sheets-Sheet 1 FiledOct. l5, 1957 @n E Q vm. .mn

mm mm. UWM. Nm'

Sept. 6, 1960 R. E. SELF 2,951,470

OSCILLATINGMACTUATOR l Filed oct. 15, 1957 2 sheets-sheet 2 INVENTOR.R/CHHRD E. `'SELF ATTORNEY-5 United States Patent OSCILLATING ACTUATORRichard E. Self, Sherman Oaks, Calif. (8354 Wilcox Ave., Bell, Calif.)

Filed Oct. 15, 1957, Ser. No. 690,336

Claims. (Cl. 121-99) This invention relates to oscilating devices of thepressure fluid type, including such devices known as actuators, whichare prime movers or motors, and dampeners or shock absorbers whererotary or vibrating-motion is dampened by restricting or metering theiiow of fluid pressure through the device, and has as its general objectto provide an improved uid sealing mechanism in such a device.

A further object of the invention is to provide an improved oscillatingdevice embodying a rotor having one or more (eg. a pair of) radial vanesprojecting (e.g. in diametrically opposite directions) from a generallycylindrical hub, and having a pair of circular end members to which theaxial extremities of said vanes are united, together with improved meansfor sealing the rotor to the mating internal surfaces of a housingembodying a generally cylindrical lateral wall portion and a pair ofdiametrically opposed reentrant partitions extending radially inwardly,in diametrically opposed relation, to the diameter of the rotor hub, anddefining the circumferential extremities of arcuate cavities in whichthe vanes of the rotor are areuately movable between limit positionsestablished by the radial sides of such partitions, the circular endmembers of the rotor being oscillatable in circular spaces betweentheaxial extremities of the partitions and the ends of the housing.

A further object is to provide, in an oscillating actuator or similardevice having the construction outlined in the preceding paragraph, animproved seal mechanism for effectively sealing the vanes of the rotorto the walls of the arcuate cavities so as to provide non-leaking fluidpressure chambers upon respective sides of each vane Within itsrespective cavity, whereby to increase the eiiiciency and the accuracyof response of the rotor to the flows .of iiuid into and out of therespective chambers, and especially to avoid bypassing of Huid from onechamber to another of a pair of adjacent iiuid pressure chambers.

In particular, the invention aims to provide a sealing mechanism whereineach of the respective fluid pressure chambers is provided with arespective seal which extends unbrokenly around the complete perimeterof the respective chamber in a. manner to seal off all crevices betweenthe rotor and the housing entirely around such perimeter. In thisrespect the invention provides a novel and important improvement overconventional sealing arrangements arranged in broken array Awithreference to the perimeters of the various fluid pressure chambers. Forexample, one common sealing Aarrangement wherein a seriesof straightsealing strips extending parallel to the rotor axis along the radiallyouter extremities of the rotor vanes, are terminated at the ends of therotor, and wheref in`a pair of circular O-rings extend unbrokenly aroundand coaxial with the rotor axis between the respective ends of the rotorand housing, has proven to be quite unsatisfactory for completelypreventing leakage between adjoining fluid pressure chambers despite allattempts to attain uid tight joints between the ends of the straightsealing strips and the ends of the housing.

ICC

Other objects and advantages will become apparent in the ensuingspecifications and appended drawings in which:

Fig. 1 is an end View of an actuator embodying the invention;

Fig. 2 is a transverse sectional view of the same;

Figure 3 is an axial sectional view of the same taken on the line 3-3 ofFig. 2 with a portion thereof shown in elevation;

Fig. 4 is an enlarged detail sectional view of a fragmentary part of therotor hub;

Fig. S is an exploded perspective view showing the assembled rotor as itwould appear without the housing and showing the housing fragmentarilyand with a portion thereof broken away and shown in section;

Fig. 6 is a fragmentary detail sectional view of an end portion of therotor taken on the line 6 6 of Fig. 5;

Fig. 7 is a fragmentary detail sectional View of the outer marginalportion of a rotor vane; and

Fig. 8 is a fragmentary sectional View of a modified form of the seal.

Referring now to the drawings in detail, I have shown v therein, as oneform in which the invention may be embodied, an oscillating actuatorembodying, in general, a rotor A (Fig. 3) and a housing B in which therotor A is mounted on an actuator shaft C (Fig. 2).

Rotor A is formed in two sections a and a' respectively7 joined end toend at a radial parting plane 10, and secured together by cap screws 11extended through bores in the section a and threaded into the section a.An O-ring 10', seated in an annular end-face groove in one of the rotorsections, maintains a hermetic seal between the rotor sections atparting plane 10. This sectional construction makes it possible toassemble the rotor within the housing B, the respective sections of therotor being inserted through respective ends of the housing Iwhich areopen during assembly, and the rotor sections being securedA to oneanother after being thus inserted into the housing.

In its assembled form, the rotor A includes a generally cylindrical hubportion 12, a pair of radial vanes 13, and a pair of circular endmembers 14, 14. The end mem# bers 14, 14 are formed integrally in therespective sec` tions a, a' and the hub 12 and vanes 13 are formed sec#tionally in the respective sections a, a', the hub and vane sectionsbeing joined integrally to the inner sides ofthe respective end members14, 14'. The vanes 13 are rectangular, extend full length between theend members 14, 14', and have radially outward faces 15, parallel Atothe rotor axis, disposed at the same diameter as the generallycylindrical peripheral faces of rim portions 16 of the end members 14,14', and merging with said periph eral faces. The rim portions 16 arejoined to the hub portions 12 of the respective rotor sections byfrustoconical end web members 17 which terminate in cylindrical hubcollars 18 (Fig. 3) defining annular recesses the bottoms of which aredefined by end shouldersV 19 of the hub sections. Y l

Extending through the hub 12, which is tubular, is a peripherallysplined central body portion 20 of the shaft C, the hub 12 havinginternal splines meshing with the splines of the body 20. At one end ofthe body 20, shaft C has an end bearing flange 21 -which seats againstone of the shoulders 19. A retainer nut 22 is threaded upon a threadedsection 23 of the other end of shaft body 20, and is tightened againstthe other shoulder 19 to maintain the rotor sections a and a and theshaft C in tight assembly.

Beyond the flange 21 and threaded section 23, shaft C has reduced,splined end studs 24, 25 respectively for torque-transmitting couplingto mechanism with which the actuator may be associated. n

` The rotor A is provided with grooves to receive four seal rings D ofirregular perimeter. Such grooves include a pair of circular grooveportions 26 in the peripheral faces of the end member rims 16, radialgroove-portions 27 in the inner faces of the fusto conical webs 17 ofthe respective end members 14, 14', joined to the respective circulargrooves 26 by short axially extending groove portions Z8 in thoseportions of the rim members 16 which lie inwardly of the grooves 26,bottom groove portions 29 extending axially in the outer faces of hub 12and joined to the inner extremities of the radial groove portions 27,and straight outer groove portions 30 in the marginal faces 15 of vanes13, extending be'- tween and joining the respective circular ,grooveportions 26. Groove portions 2 7, 28 and 29 have a common widthsubstantially twice the cross sectional diameter of the seal rings D,and accommodate stretches 31, 32 and 33 of two adjoining seal ringslying side by side as shown in Fig. 5. The groove portions 27, 28 and 29are duplicated on both sides of the rotor in diametrically opposedrelation, the adjoining streches 31, 32 and 33 of the seal rings D inthese groove portions being in contact with one another on a common`diametral plane of the rotor axis. Groove portions 3i) (Fig. 7) likewiseare of substantially twice the width of theseal ring cross section andaccommodate contacting outer straight stretches 34 of adjacent sealrings extending, at the periphery of the rotor, between the 90 quadrantVend stretches 35 of respective seal rings, which end stretches 35 ineach seal ring join the ends of outer straight stretch 34 thereof to theshort axial portions 32.

The housing B comprises a cylindrical lateral portion 36 having thereina pair of diarnetrically opposed housing portions 37 and 37. The housingportions 37 and 37' comprise respective pairs of radial wall portions38, 38', pairs of end wall portions 39 and respective quartercylindricalbottom wall portions 4t), v10. The radial portions 38, 38 have radialinner walls which define the limits of arcuate swinging movement ofrotor vanes 13, and cooperate with the vane 13, the hub 12, the lateralhousing wall 36 and the rotor end members 14, 14' to define fluidpressure chambers 41 (Fig. 2). The

bottom wall members 40, 40' have quarter-cylindrical inner faces whichare fitted to the hub` 12 so as to be swept by and constantly sealed tothe straight bottom stretches 33 of the seal rings D. The quartercylindrical portions of lateral wall member 36 bridging between theradial wall members 38, 38 have quarter-cyclindrical inner walls 36which are fitted to the straight outer margins 15 of the vanes 13 so asto be swept by and in constant sealing contact with the outer straightstretches 34 of the seal rings D. The radial portions 31 and 32 of theseal rings are in sealing engagement with the end wall members 39 of thehousing housing portions 37, 37', and with end portions 36a of thelateral walls 36 which are continuously cylindrical throughout thecircumference of the housing. The arcuate end portions 35 of the sealrings seal against the cylindrical inner walls of the end housingportions 36a.

It will now be apparent that each of the -four fluid pressure chambers`41 is completely circumscribed by a respective seal ring D whichprovides a continuous huid seal between the adjoining parts of the rotorand the housing around the complete perimeter of the respective chamber41, regarded as being extended at its bottom in the narrow arcuateclearance space between the hub '12 and the bottom wall 40 (or 40') tothe bottom stretch 33 of the respective seal ring. Since the fluidpressure chamber is thus circumscribed completely by a continuous sealring, there is no point Where any leakage of fluid from one chamber toan adjacent chamber can occur and there is no point where leakage fromthe end of the housing can occur.

The housing B is provided with respective end caps 4Z tted into theannular recesses defined in the respective ends of rotor A and each isprovided with a cylindrical rim 43 having an annular shoulder whichbears against a gasket ring 44 sealing the cap in a counterbore 45 inthe cylindrical end portions 36a of the housing, each cap 142, beingthreaded into a respective counterbore 45, and each having a radialinner end collar provided with an annular internal groove receiving anO-ring 46 by means of which it is sealed to the hub collar 18 of rotorA.

In one of the end caps 42. there is provided a fluid pressure port 47(preferably a single port as shown in Fig. 3) which conveys pressure uidfrom a pressure line of the system to the end space between that end capand the adjacent end of the rotor. Such pressure fluid, bleeding throughthe annular crevice 16 between rotor rim 16 and the housing end 36a,will travel in the crevices between the adjoining seal stretches 33 and34 (forcing them apart, amplifying their cross-sectional distortion, andincreasing their sealing efliciency) and will reach the annular endspace between the opposite end of the rotor and its adjacent end cap,thus endloading the sections of the rotor at both ends to maintain tightcontact at the parting plane 10, As shown in Fig. 1, several pressureports 47 may be optionally provided in respective end bosses 43 whichmay be drilled and tapped as indicatedl in Fig. 1 for attachment ofrespective connections to a fluid pressure line. The end studs 24 and 25are adapted for driving connection with instruments or other parts ofapparatus in either driving or driven connection with the actuator.

In the housing portion 37 of the housing B, there are provided fluidinlet and outlet ports 49 the outer end of which may be counterbored andtapped as indicated, for attachment of iluid line fittings through whichuid may be directed into one of the chambers 41 and drained from analternate chamber. Transfer ports 50 extend diagonally through the rotorA to provide intercommunication between diametrically opposite, pairedchambers 41 so that uidv pressure applied to one chamber of a pair issimultaneously transmitted to the other chamber of the pair while thefluid in the alternate pair of chambers is drained from the remotechamber of that pair to the near chamber directly connected with a uidport 49 and thence from the near chamber through such port 49.

The housing, on the sides adjacent the ported reentrant section 37', maybe provided with lips 51 for purposes of side mounting the actuatoragainst a flat wall through which the tduid lines may extend.

As shown in Fig. 8, the seal rings, instead of being of 0ring crosssection and of soft, compressible material, retained in a groove as inFigs. 1-7, may be of thin ribbon metal of spring metal characteristic,welded, brazed or otherwise secured and sealed to the various surfacesof rotor A along the same contours as in Figs. 1-7, and in fluidpressure energized and yielding spring pressure contact with the opposedsurfaces of casing B,

for high-temperature operation.

As shown, the seal rings D' are preferably seated in grooves in thevarious rotor surfaces as in the preferred form of the inventionpreviously described, including groove portions 30' extending axially inthe marginal outer extremity faces 15 of vanes 13', leaving bearinglands on both sides of the groove portions, for'positive positioning ofthe rotor within the housing, with all torque reaction loads, radialloads, etc., being taken between such bearing lands and the matingsu-rfaces of the housing.

While a device embodying a two-vane rotor and a housing whichcorrespondingly has vane chambers and separating partitions each ofquadrant extent, it will be understood that the invention can beembodied in a single-vane device having a vane chamber and a partitionmember both of greater than 90 extent, or in a device having three ormore vanes and corresponding vane chambers and partitions of less than90 arcuate extent.

I claim:

1. A device of the type described that comprises a rotor including arotor shaft, a housing enclosing said rotor and supporting said rotorand shaft for oscillation therein, said rotor having a center portion ofgenerally cylindrical shape and end portions of generally circular shapeand of larger diameter than said center portion, and at least one vaneextending radially and axially from said center portion and between saidend portions to aA radius substantially equal to that of said endportions, said housing having at -least one housing portion extendingaxially and radially of said rotor into the space provided between saidend portions of said rotor and the wall of said housing and said centerportions of the rotor, thus, dividing the space between the centerportion of the rotor and the housing into at least two pressurechambers, said housing having pressure openings into each of saidchambers, a continuous gasket extending along the outer surface of theaforementioned vane to the circular end portions of the rotor, thence,peripherally around the circular end portions of the rotor to a positionthat will be opposite to the aforementioned housing portion in anyposition of oscillation of the rotor, and from there down the innerfaces of the said end portions and across the center portion to completethe continuity.

2. A device of the type defined in claim l further characterized in thatat least two continuous gaskets are provided which extend along theouter surface of the vane to the circular end portions of the rotor, andthence peripherally in opposite directions around the circular endportions of the rotor to positions that will be opposite to said housingportion in any position of oscillation of the rotor, and from there downthe inner faces of the end portions and across the center portion tocomplete the continuity of each of the two continuous gaskets.

3. A device as defined in claim 2 in which the gaskets are held incontinuous grooves in the rotor surface.

4. A device as dened in claim l further characterized in that the rotorhas at least two vanes and the housing has at least two portions thusforming at least four pressure chambers, two of which are connectedthrough openings in the housing and the other two of which are connectedto the first two through openings in the rotor, the rotor in thisinstance carrying at least four gaskets, each gasket being continuousand extending longitudinally along the outer surface of a vane and thenalong the outer surface of the two end members to a position that willbe opposite to one of said housing portions in any position ofoscillation of the rotor and from there down the inner face of the endportion and across the hub to complete the continuity.

5. A device as deined in claim 4 in which the gaskets are held incontinuous grooves in the rotor surface.

References Cited in the le of this patent UNITED STATES PATENTS 540,492Humes June 4, 1895 2,164,876 Horlacher Iuly 4, 1939' 2,569,640 Mercieret a1. Oct. 2, 1951

